Summary :
While in «art» and «traditional» music, the nimbleness of the voice and the mastering of the vocal tone are put into pers­pective, in «popular» music, sound engineering takes the lead, and relegates the vocal virtuosity of the interpreter to second place. We propose to study here three technologies with contri­butions to music. All are developed and patented by the Bell Labs: The artificial larynx (and its derivatives, Sonovox and TalkBox), the vocoder and the speech synthesis. After a presen­tation of the source-filter theory, vital to these innovations, the principle of these three technologies is explained. A brief historical is outlined and is complemented by examples of films and musical selections depicting these processes. In light of these elements, we conclude: Sound engineering, and in parti­cular the modification of voice sonority, has become an indis­pensable component in the process of «pop» artistic musical creation.